1. Field of the Invention
The present invention relates to machines for manufacturing containers, and more particularly, to a machine that attaches fitments, resealable or otherwise, to containers such as paperboard containers and sterilizes the container while both ends of the container are open prior to further forming, filling and sealing of the container.
2. Description of the Related Art
Manufacturers are increasingly using paperboard containers as alternative packaging to cans, bottles and other receptacles for food, beverage and non-food products. Typically, paperboard containers are coated with a heat-sealable substrate and are formed, filled and sealed using a machine such as the prior art machine 10 depicted in FIG. 1. As illustrated therein, flat blank containers 12 stored in a magazine 14 are opened, squared and placed onto forming mandrels 17 in a bottom sealing station 16. Thereafter, the bottom end of the container is preformed, heated and pressure sealed. Other package-forming steps such as preforming the top end also may be undertaken as the bottom end is sealed.
Containers 12 are then discharged from station 16 and placed on a conveyor 18 for transport to a conventional filling station 20 where containers 12 are filled with product. Thereafter, containers 12 pass through a conventional top sealing station 22 where the top flaps are heated, closed and pressure sealed.
The operation of machines 10 is schematically depicted in FIG. 2. Flat, blank containers 12 are stored in a magazine at step S.sub.1. Subsequently, they are removed from the magazine and opened and squared at step S.sub.2. Thereafter, the bottom flaps of container 12 are preformed at step S.sub.3 and heated at step S.sub.4. The bottom flaps are then sealed (and the top flaps are preformed) at step S.sub.5. At step S.sub.6, the container 12 is outfeeded to the conveyor. Next, container 12 is filled with product at step S.sub.7, transported to step S.sub.8 where the top flaps are heated, and then to step S.sub.9 where the top flaps are sealed. At step S.sub.10, a date code can be stamped on container 12, if desired.
Consumers usually open conventional gable-top paperboard containers by splitting apart one side of the gable-top seal and pulling out the gussets from the center of the split seal to expose the container's built-in pour spout. Once opened, the gable-top container cannot be resealed effectively. As a result, the contents of the container can leak or spill if, e.g., the container is stored on its side or is unintentionally knocked over or shaken. In addition, product stored in an opened gable-top container 12 is more susceptible to spoilage or contamination. In addition, some gable-top seals are very difficult to open because of the substrates utilized, thereby necessitating access to the product without opening the gable-top seal. To overcome these problems, pouring spouts with reclosable caps and other fitments (e.g., plastic patches which may be punctured for access to the product) have been added to paperboard containers.
FIG. 3 shows a prior art form, fill and seal machine 24 with an applicator station for attaching capped spouts to paperboard containers. Details of the workings of prior art machines with capped spout applicators such as machine 24 are available in U.S. patent application Ser. No. 07/783,038, filed on Oct. 25, 1991 and entitled "Method and Apparatus For Attaching a Spout to a Container," the contents of which are hereby incorporated by reference. As depicted in FIG. 3, flat, blank containers 26 previously loaded in a magazine 28 are individually withdrawn, opened, squared and placed onto forming mandrels. Subsequently, the bottom flaps of the container 26 are heated, formed and pressure sealed in a conventional manner within a forming station 30. After its bottom end is sealed, container 26 is outfed to a conveyor 32 and transferred to a location adjacent a spout application station 34. There, a capped spout 36 is inserted through a preformed hole in container 26 and attached to the inner wall of container 26. Alternative methods are available for attaching the spout to the outer wall of the container, too. Container 26 then continues travelling on conveyor 32 to a conventional filling station 38 where it is filled with product. Thereafter, the container 26 is transported through a gable-top sealing station 39. There, its top flaps are heated, closed and pressure sealed.
The packaging of food and beverage products poses certain contamination risks. In addition, food and beverage producers are constantly working to extend shelf-life of perishable products. These two concerns often necessitate sterilization or cleansing of the container prior to its being filled with product. In existing machines, containers typically are sanitized after the bottom flaps of the container have been folded and sealed, and just prior to filling the container with product. Cleansing techniques include the use of ultraviolet ("UV") light, chemical solutions (e.g., hydrogen peroxide), steam, or a combination of two or more of these techniques.
Existing cleansing techniques have an inherent drawback in that cleansing occurs after one end (usually the bottom end) of the container has been folded and sealed. For example, while UV light can effectively disinfect surface contaminants such as bacteria, yeast, mold and spores, it is only effective on contaminants that are exposed to and penetrated by the UV light. Therefore, UV light may not effectively disinfect certain portions of a partially formed container, e.g., folded edges and corners. Thus, a technique for more effectively sterilizing paperboard containers is desirable.
Chemical and steam cleansing techniques have similar drawbacks. The chemical or steam wash occurs after one end of the container (again, usually the bottom end) is folded and sealed. Therefore, it is possible for contaminants or chemical residue to become trapped in the container. Chemical and steam cleansing treatments also require an additional drying station for the container prior to the fill station.
Chemical and steam cleansing are problematic for additional reasons. Over time, chemical fumes and steam may cause electronic components operating within existing machines to malfunction. Also, in existing machines, cleansing occurs immediately prior to, and adjacent, the filling of the container. As a result, chemicals, which may be detrimental to the product, are immediately adjacent the fill area. This placement introduces the risk of the chemicals being introduced into the fill area via, e.g., splashing or lingering residue on the container.
In addition, industrial safety hazards created by the use of chemicals, as well as governmental regulations relating to effluent discharge are causing manufacturers to consider alternative cleansing techniques.
In addition to the aforementioned problems, paper fiber and other particles from manufacturing the blank container may reside on the inner wall of the flat container. Because existing sanitation techniques occur after the bottom end of the container has been sealed, a likelihood exists that such particles will remain in the container after cleansing has occurred. And, if these particles become lodged in an edge or corner of the bottom of the container, common cleansing techniques may not completely disinfect such particles.
Adding stations (such as fitment applicator and cleansing stations) to a packaging machine also can lead to production inefficiencies. The length of machines with fitment applicators and cleansing stations can be a problem for users of existing packaging machines who have limited floor space, especially if the user is operating several packaging machines. Although some existing machines do have excess space for either an applicator or a cleansing station, few can accommodate both without further lengthening of the machine. In addition, statistical analysis reveals that each station in a packaging machine will malfunction a certain percentage of the time. Therefore, the more stations contained within a single machine, the higher the probability for a defective output. For example, if a container is inserted into the magazine backwards, the machine will not be able to properly attach the spout. Nevertheless, the backward container will still pass through a number of stations even though there is no chance of a successful product output. However, if the tasks of a single machine are divided among two or more machines, an error or malfunction at one station is not propagated to all of the subsequent stations. A problem container can be removed in an early stage of production. Thus, stations on the next machine have a higher probability of receiving proper containers as input. By dividing the stations among multiple machines, higher efficiencies and lower errors are achieved.
While spout applicator and sanitation stations incorporated into form, fill and seal machines are desirable to users of packaging machines, prior to the present invention, many machines could not accommodate these additional features. Thus, many users must purchase new form, fill and seal machines to obtain these additional capabilities. However, such machinery can be expensive. In addition, some users are reluctant to switch to machines with these additional features because they have not yet recovered the capital investment made for their currently owned form, fill and seal machines.
At least one prior art machine attaches a spout to an open-ended container as disclosed in U.S. Pat. No. 4,788,811. However, the spout is first introduced into the preformed opening in the container and later attached to the container. This two-step process may result in the occasional occurrence of defectively attached spouts due to disengagement of a spout from the hole prior to its attachment to the container. In addition, the horizontal positioning of the container prior to sealing one of its open ends subjects the container to the same cleansing problems as described above.
Therefore, a need exists for a novel apparatus that can be used in conjunction with existing form, fill and seal machines to achieve fitment capability and enhanced sanitation. Such a machine ideally would require minimal modification to an existing form, fill and seal machine such as machine 10.